A kind of engine bleeder valve tappet dynamic vibration stress measurement of comparison method
【Technical field】
The invention belongs to aero-engine test technology fields, and in particular to a kind of engine bleeder valve tappet dynamic
Vibration stress measurement of comparison method.
【Background technology】
Many aero-engine engine surges in the range of specific rotation speeds in order to prevent, equipped with air-release mechanism, engine
The opening and closing of air bleed valve are the important mechanisms of engine anti-asthma, perform the tappet rocking arm bearer for manipulating valve work
A variety of load, the quality of fatigue properties directly affect the normal work of engine.
Air bleed valve tappet is the connecting rod that air bleed valve movement is driven during air-release mechanism effect, and the prior art usually exists
Unit status simulated engine operating status measures.Air-release mechanism general structure, stress are complicated residing for tappet, and theoretical calculation is difficult
With accurately draw tappet work when stressing conditions, if air bleed valve tappet fracture or because other reasons need to measure it is servo-actuated
Dynamic vibration stress intensity at bar, difficulty are larger.
【The content of the invention】
It is put in view of the above-mentioned deficiencies in the prior art, the technical problem to be solved by the present invention is that providing a kind of engine
Gas valve tappet dynamic vibration stress measurement of comparison method, can in actual work measure, data are accurate, to putting in engine
The dynamic strain of gas valve tappet privileged site carries out measurement of comparison, by the way that its stressing conditions is calculated, and can be more
Secondary measurement compares and analyzes.
The present invention uses following technical scheme:
A kind of engine bleeder valve tappet dynamic vibration stress measurement of comparison method, including:
Step 1, using tappet fracture location back as measurement point;
Step 2 determines strain gauge adhesion position and the conversion coefficient of tappet fracture location by testing;
Step 3 drills in air bleed valve tappet spindle central position, draws foil gauge data cable, and tappet examination is made
Test part;
Step 4 takes the mode after corrective measure that tappet testpieces is assembled to engine, in engine test,
Test run is carried out by test program, measures strained at tappet patch in real time;
Step 5, according to measurement demand, simulate the engine condition before corrective measure, engine be adjusted in ride;
Step 6 after having adjusted engine, carries out secondary test run by identical test program again, measures tappet patch in real time
It is strained at piece;
Step 7, by being calculated measurement data, comparative analysis, obtain result.Further, coefficient in the step 2
Concrete mode is tested in conversion:A tappet is chosen, the patch location at the position and experiment for needing to measure is sticked should
Become piece, by a force application apparatus it is made to generate strain, so as to the conversion coefficient for drawing measuring point He needing position.
Preferably, in the step 3 tappet spindle central location hole be through hole, the hole internal diameter for 2.0mm~
2.5mm。
Preferably, in the step 4 in test program, when engine is run to 78%~86% high pressure rotating speed, progressively
Engine speed is promoted up to military state, then reduces engine speed successively.
Preferably, the adjustment mode of engine is in the step 5, engine leave office decompose after, when ressembling into
Row adjustment.
Compared with prior art, the present invention at least has the advantages that:
(1) engine part change is few:It only needs to be transformed tappet in itself processing, remaining parts, which can be used, starts
Machine original platform part.
(2) it is accurate to measure conclusion:Measuring point is drawn with the conversion coefficient at position is needed to be checked by calculating, testing
Measure conclusion accurately and reliably.
(3) measurement data is continuous:The measurement is measured in real time during engine test, and the data of acquisition are coherent song
Line is conducive to the data analysis in later stage.
Below by drawings and examples, technical scheme is described in further detail.
【Description of the drawings】
Fig. 1 is air bleed valve tappet schematic diagram of the present invention;
Fig. 2 is air bleed valve tappet testpieces schematic diagram of the present invention;
Fig. 3 is air bleed valve tappet strain gauge adhesion position view of the present invention;
Fig. 4 is the assembling schematic diagram of air bleed valve tappet of the present invention on the engine;
Fig. 5 is the tappet stress curve figure measured under two kinds of engine conditions of the invention.
Wherein:1. tappet;2. foil gauge;3. breaking part.
【Specific embodiment】
Shown in please referring to Fig.1 to Fig.3, the invention discloses a kind of engine bleeder valve tappet dynamic vibration stress pair
Ratio measuring method, step:
(1) measurement point is determined:Because 1 structure of tappet and assembling situation are limited, tappet 1 need to measure the general nothing in stress position
Method pastes measuring foil gauge, and stress position back side corresponding position progress patch need to be measured by being usually chosen in tappet 1.
(2) conversion coefficient is determined:Position is pasted due to foil gauge 2 and is not required to position, by 2 paste section of foil gauge
The strain of position, which is scaled to, needs position, and conversion coefficient can be obtained by way of calculating or testing, and is specially:One is chosen to be servo-actuated
Bar, the patch location at the position and experiment for needing to measure stick foil gauge, and generating it by a force application apparatus should
Become, so as to the conversion coefficient for drawing measuring point He needing position.
(3) tappet testpieces is made:After being assembled due to tappet 1, foil gauge 2 pastes position and breaks positioned at engine interior
Place 3 is split, to conducting wire is drawn engine, tappet 1 need to accordingly be processed, i.e., bores one in 1 specific position of tappet
Through hole, hole internal diameter is that the concentricity at 2.0mm~2.5mm, with A is 1.0mm, in favor of the extraction of conducting wire.Being pasted after drilling should
Become piece 2, testpieces is made.
(4) measuring strain:Tappet testpieces is assembled to engine, it is high by 78%~86% in engine test
Rotating speed test program is pressed to carry out test run, measures strained at tappet patch in real time.
(5) engine is adjusted:According to measurement demand, engine is adjusted in ride.It if it is desired, can be in engine
It leaves office after decomposing, related adjustment is carried out when ressembling.
(6) second of test run:After having adjusted engine, test run is carried out by identical test program again, it is servo-actuated to implement measurement
It is strained at bar patch.
(7) data analysis:By being calculated measurement data, comparative analysis, obtain result.
Refer to shown in Fig. 4, when need to measure air bleed valve movement using certain model engine tappet stress compare situation as
Example:After air bleed valve tappet fracture defect finds out failure cause and corrective measure, the validity of corrective measure need to be carried out
Verification, stressing conditions when need to work the forward and backward tappet of corrective measure carry out measurement of comparison.Tappet schematic diagram is shown in Fig. 1, surveys
Measuring step is:1) measurement point is determined:Measurement point is determined in tappet fracture location back corresponding position.2) conversion coefficient is determined:
By way of experiment, the conversion coefficient of strain gauge adhesion position and tappet fracture location is determined.3) tappet experiment is made
Part:As shown in Fig. 2, drilling in tappet spindle central position, in favor of the extraction of conducting wire, foil gauge is pasted after drilling, is such as schemed
3, testpieces is made.4) measuring strain:Tappet testpieces is assembled to engine, when assembling takes the mode after corrective measure
Assemble engine.In engine test, specific test program is worked out, when engine is run to about 78% high pressure rotating speed, by
Step promotes engine speed up to military state, then reduces engine speed successively, in the process in real time at measurement tappet patch
Strain.If data acquisition effect is undesirable, this measurement process can be repeated.5) engine is adjusted:In ride to engine phase
It closes part to be adjusted, simulates the engine condition before corrective measure.6) second of test run:After the completion of adjustment, by identical test run
Program carries out second of test run, and tappet stress is measured in commissioning process;7) data analysis:By being counted to measurement data
It calculates, comparative analysis, obtains result.
It refers to shown in Fig. 5, top is divided by the stress level measured after assembly method assembling engine before corrective measure
Graph, lower part are divided into the stress level graph for starting rear measurement by assembly method assembling after corrective measure, can from figure
To see, assembling engine stress level is higher before corrective measure, and assembling engine stress level is relatively low after corrective measure, this side
Air bleed valve tappet carries out dynamic stress measurement of comparison when method is to Engine pedestal trial run, reliable and effective can draw engine
The stressing conditions of air bleed valve tappet during different assembled states, really reflect its working condition;Finally measure the data drawn
For complete curve, data analysis can be carried out to any point, be easily mastered the abnormal stressing conditions of tappet at work;Test run
Test program is identical in the process, and the curve that measurement result is formed is similar, convenient for comparative analysis;It only needs to carry out tappet during experiment
Transformation processing, experimentation cost are low.